Apparatus and method for chained arbitration of a plurality of inputs

Abstract

An apparatus for chained arbitration of a plurality of inputs for access to a shared resource is provided. The apparatus includes a plurality of levels of arbiters including a first arbitration level having at least one first level arbiter, and a second arbitration level having at least one second level arbiter, the at least one first level arbiter comprising a locker module for generating a lock request signal to the at least one second level arbiter after locking one of the plurality of inputs, the at least one second level arbiter comprising a grant module for generating a grant signal to the at least one first level arbiter in response to the lock signal, whereby upon receipt of the lock signal the at least one first level grants access to the at least one second level arbiter for the locked one of the plurality of inputs.

1 . An apparatus for chained arbitration of a plurality of inputs for access to a shared resource, the apparatus comprising:
 a plurality of levels of arbiters comprising a first arbitration level having at least one first level arbiter, and a second arbitration level having at least one second level arbiter;   the at least one first level arbiter comprising a locker module for generating a lock request signal to the at least one second level arbiter after locking one of the plurality of inputs; and   the at least one second level arbiter comprising a grant module for generating a grant signal to the at least one first level arbiter in response to the lock request signal;   whereby upon receipt of the lock request signal, the at least one first arbiter level grants access to the at least one second level arbiter for the locked one of the plurality of inputs.   
     
     
         2 . The apparatus as claimed in  claim 1 , wherein an output of the at least one first level arbiter is input to the at least one second level arbiter. 
     
     
         3 . The apparatus as claimed in  claim 1 , wherein the at least one first level arbiter comprises a plurality of first level arbiters, the number of first level arbiters being determined by the number of inputs. 
     
     
         4 . The apparatus as claimed in  claim 3 , wherein the number of second level arbiters is determined by the number of first level arbiters and a number of further inputs to the at least one second level arbiter. 
     
     
         5 . The apparatus as claimed in  claim 4 , wherein the further inputs are of an order of priority higher than that of the plurality of inputs. 
     
     
         6 . The apparatus as claimed in  claim 5 , further comprising at least one third level arbiter in a third arbitration level, wherein the at least one third level arbiter receives a number of additional inputs of a higher order of priority than the further inputs. 
     
     
         7 . The apparatus as claimed in  claim 1 , further comprising at least one third level arbiter in a third arbitration level for receiving an output from the at least one second level arbiter. 
     
     
         8 . The apparatus as claimed in  claim 1 , wherein the number of levels in the plurality of levels is at least as great as a number of orders of priority of the plurality of inputs. 
     
     
         9 . The apparatus as claimed in  claim 1 , wherein the number of the plurality of levels and the number of inputs at each level are independent of each other. 
     
     
         10 . An apparatus for chained arbitration of a plurality of inputs for access to a shared resource, the apparatus comprising:
 a plurality of levels of arbiters comprising a first arbitration level having at least one first level arbiter, and a second arbitration level having at least one second level arbiter;   the at least one second level arbiter comprising a grant module for generating a grant signal to the at least one first level arbiter;   the at least one first level arbiter arbitrating the plurality of inputs in response to the grant signal; and   the at least one first level arbiter comprising a locker module for generating a lock signal to the at least one second level arbiter in consequence of the arbitration.   
     
     
         11 . A method for chained arbitration using a plurality of arbiters in a plurality of levels, the method comprising:
 at least one first arbiter in a first level receiving a plurality of input requests for access to a shared resource;   the at least one first arbiter generating a lock request and sending it to at least one second arbiter in a second level;   the at least one second arbiter generating a grant signal and sending it to the at least one first arbiter; and   the at least one first arbiter granting access to the at least one second arbiter for one of the plurality of input requests.   
     
     
         12 . The method as claimed in  claim 11 , wherein the lock request is generated and sent by the at least one first arbiter after receiving the grant signal. 
     
     
         13 . The method as claimed in  claim 12 , wherein before generating the lock request and sending it to the at least one second arbiter, the at least one first arbiter performs an arbitration of the plurality of input requests. 
     
     
         14 . The method as claimed in  claim 11 , wherein one of the plurality of input requests is locked before the lock request is generated and sent. 
     
     
         15 . The method as claimed in  claim 11 , wherein there are a plurality of first arbiters in the first level, the number of first arbiters in the first level is determined by the number of inputs. 
     
     
         16 . The method as claimed in  claim 11 , wherein there are a plurality of second arbiters in the second level, the number of second arbiters in the second level is determined by the number of first arbiters in the first level and a number of further inputs to the plurality of second arbiters. 
     
     
         17 . The method as claimed in  claim 11 , further comprising at least one third arbiter in a third level.